1. An Efficient Spatial Prediction-Based Image Compression Scheme
Chin-Hwa Kuo, Tzu-Chuan Chou, and Tay-Shen Wang,
IEEE Transactions on Circuits and System for Video Technology, Vol.12, No.10, October 2002, pp
Advisor : Prof. Chang, Chin-Chen
Speaker: Lee, Jiau-Yun
Date : 2003/6/3

2. Outline Introduction Spatial Prediction-Based Image Compression
Proposed Spatial-Prediction Scheme
Experimental Results
Conclusions

3. Introduction
DWT has become the important technology of image compression.
ESPIC can fit for the application to real-time and wireless multimedia environment.

4. The Typical Spatial Coding System
Symbol
encoder
compressed image + -
Input
image
Nearest
integer
predictor
decompressed image
Compressed
image
Symbol
decoder +
predictor
Prediction error

5. Spatial Prediction-Based Image Compression
The typical spatial coding system can’t use all pixel to predict.
We break the limit and extend to lossy image compression. c b a x

6. Proposed Spatial-Prediction Scheme(ESPIC)
The design efficient spatial prediction-based image compression(ESPIC) consists two phases:
Phase1---Prediction
Construct hierarchical structure
Prediction scheme
Phase2---Quantization

7. Construct Hierarchical Structure
Step1:mark position as n
(row num.+column num.=even)
Step2:mark position as n+1
(row num. :even & column num. :odd)
preprocess:
Set all pixels as 0 and n=1 1 2 1 2 3 4 5 6 7

8. Construct Hierarchical Structure(Cont.) 1 2 3 4 5 6 1 2 3 4 5 6 7
Step3: collect still marked as 0 and combine them into a new small image
Step4: reassign new row and column num.
Step5: n=n+2 go to step1 3 4 1 2 3 5 6

9. Construct Hierarchical Structure(Cont.)
temporary map 1 2 3 4 5 6
Level4
Level3
Level2
Level1
Position number
1 32
2 16
3 8
4 4
5 2
6 1

10. Prediction Scheme---Mark Number
n is odd number:
n+1:
<temporary map>

11. Example---Sender <original> 1 2 3 4 5 6 7 1 1 2 3 4 5 6 7
100
120 80 70 90
200 50
220
110 60 30 1 2 1 2 3 4 5 6 7 10
32.5
17.5 40
37.5
62.5 55
-7.5 -5
-12.5
-40
-42.5
-20
-25 15
57.5
87.5
-57.5
-105
-52.5
-102.5
-35
-80
-82.5 70
100
-15
-30
7.5
-2.5
-22.5 1 2 3 4 5 6 7
0 = 80-(1/4( ))
= 50-(1/4( ))

12. 1 2 3 4 5 6 7
100
120 80 70 90
200 50
220
110 60 30 1 2 3 4 5 6 7 1 2 3 4 3 4 10
32.5
17.5 40
37.5
62.5 55
2.5
-25
-17.5
-7.5 -5
-12.5
-40
-42.5
-20 15
57.5 80
87.5
-57.5
-105
-52.5
-102.5
-35
-80
-82.5
102.5 70
125
100
-37.5 5
-15
-30
7.5
-2.5
-22.5 1 2 3 4 5 6 7
-12.5=90-(1/4( ))
5=100-(1/4( ))

13. 1 2 3 4 5 6 7
100
120 80 70 90
200 50
220
110 60 30 1 2 3 4 5 6 7 1 2 3 4 5 6 3 4 10
32.5
17.5 40
37.5
62.5 55
2.5
-25
-17.5
-7.5 -5
-12.5
-40
-42.5
-20 15
140
57.5 80
87.5
-57.5
-105
-52.5
-102.5
-35
-80
-82.5
102.5 70
125
100
-37.5 5
-15
-30
7.5
-2.5 60
-22.5
-100 5 6 1 2 3 4 5 6 7
-40=90-(1/2(200+60))
140=200-60

14. Example---Receiver 1 2 3 4 5 6 7 1 2 3 4 5 6 7 5 6 200 = 60+140 1 2 3 4 5 6 1 2 3 4 5 6 7 10
32.5
17.5 40
37.5
62.5 55
2.5
-25
-17.5
-7.5 -5
-12.5
-40
-42.5
-20 15
140
57.5 80
87.5
-57.5
-105
-52.5
-102.5
-35
-80
-82.5
102.5 70
125
100
-37.5 5
-15
-30
7.5
-2.5 60
-22.5
-100 1 2 3 4 5 6 7 3 4 1 2 3 4 5 6 7 90
200 60 30 5 6
200 =
90 = -40+(1/2(60+200))

15. 10
32.5
17.5 40
37.5
62.5 55
2.5
-25
-17.5
-7.5 -5
-12.5
-40
-42.5
-20 15
140
57.5 80
87.5
-57.5
-105
-52.5
-102.5
-35
-80
-82.5
102.5 70
125
100
-37.5 5
-15
-30
7.5
-2.5 60
-22.5
-100 1 2 3 4 5 6 7 1 2 3 4 5 6 7 1 2 3 4 5 6 1 2 3 4 5 6 7 70 90
200
220
100 60 30 3 4
220 = 125+ (1/4( ))

16. Quantization The higher level pixels affect more pixels
They have higher significance.
The hierarchy is similar to the hierachy made by DWT.
The authors combine prediction scheme and SPIHT algorithm.
It can use progressive codec.

17. Quantization Round1: pass 60,140,0,0 … 1 2 3 4 5 6 7 10 32.5 17.5 40
37.5
62.5 55
2.5
-25
-17.5
-7.5 -5
-12.5
-40
-42.5
-20 15
140
57.5 80
87.5
-57.5
-105
-52.5
-102.5
-35
-80
-82.5
102.5 70
125
100
-37.5 5
-15
-30
7.5
-2.5 60
-22.5
-100 1 2 3 4 5 6 7
Round1: pass 60,140,0,0 …

18. Experimental Results

19. Experimental Results(Cont.)

20. Conclusions
The ESPIC scheme has compression efficiency and progressive coding.
The developed scheme is benefit to the application of real-time and wireless image transmission.